Scrabster to Stromness ferry (Scotland) only schedules Southbound. Will not accept Northbound route

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https://abrp.upvoty.com/b/report-a-bug/scrabster-to-stromness-ferry-scotland-only-schedules-southbound-will-not-accept-northbound-route/
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ABRP appears to refuse to plot a route northbound on the Scrabster to Stromness ferry (Northern Scotland to Orkney). It works fine for the return journey, Southbound. Is this a bug?
(Currently, ABRP is forcing the route to the normally-available Pentland Ferries crossing from Gills Bay to St Margaret's Hope, but that service is currently suspended so I must travel Scrabster - Stromness.)